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Background: Chinese hamster ovarian (CHO) cells are widely employed in biotechnology for the production of recombinant proteins. Extending the life span of CHO cells and inhibiting the loss of producing cell population through the inhibition of apoptosis can benefit the productivity of those cells. In this study, we aimed to screen and evaluate the impact of some caspase-7 inhibitor candidates on the lifespan of CHO cells. Results: Through virtual screening and molecular docking, risperidone was screened and selected as a potential inhibitor of caspase-7 in CHO cells. The results of MTT assay revealed that the cytotoxicity of risperidone at all concentrations was lower than 50%, and thus it can be suggested as a safe treatment for CHO cells. Annexin V apoptosis and flow cytometry assays revealed that risperidone at 1, 25, and 50 lM concentrations inhibited apoptosis 72 h post-treatment through caspase-7 inhibition. Although gene expression analysis through qRT-PCR demonstrates that risperidone did not affect caspase-7 gene expression. Conclusions: This bioinformatics and experimental study suggests risperidone as a caspase-7 inhibitor with the potential to extend the lifespan of CHO cells and offers possible opportunities in biotechnology. [ABSTRACT FROM AUTHOR]

Background: Chinese hamster ovarian (CHO) cells are widely employed in biotechnology for the production of recombinant proteins. Extending the life span of CHO cells and inhibiting the loss of producing cell population through the inhibition of apoptosis can benefit the productivity of those cells. In this study, we aimed to screen and evaluate the impact of some caspase-7 inhibitor candidates on the lifespan of CHO cells. Results: Through virtual screening and molecular docking, risperidone was screened and selected as a potential inhibitor of caspase-7 in CHO cells. The results of MTT assay revealed that the cytotoxicity of risperidone at all concentrations was lower than 50%, and thus it can be suggested as a safe treatment for CHO cells. Annexin V apoptosis and flow cytometry assays revealed that risperidone at 1, 25, and 50 µM concentrations inhibited apoptosis 72 h post-treatment through caspase-7 inhibition. Although gene expression analysis through qRT-PCR demonstrates that risperidone did not affect caspase-7 gene expression. Conclusions: This bioinformatics and experimental study suggests risperidone as a caspase-7 inhibitor with the potential to extend the lifespan of CHO cells and offers possible opportunities in biotechnology.How to cite: Kafi S, Najafi S, Mahnam K, et al. Virtual screening and experimental analysis of caspase-7 inhibitors as candidates for extending the lifespan of CHO cells. Electron J Biotechnol 2024;71. https://doi.org/10.1016/j.ejbt.2024.04.007.

The innate immune system serves as the first line of defense against β-coronaviruses (β-CoVs), a family of viruses that includes SARS-CoV-2. Viral sensing via pattern recognition receptors triggers inflammation and cell death, which are essential components of the innate immune response that facilitate viral clearance. However, excessive activation of the innate immune system and inflammatory cell death can result in uncontrolled release of proinflammatory cytokines, resulting in cytokine storm and pathology. PANoptosis, innate immune, inflammatory cell death initiated by innate immune sensors and driven by caspases and RIPKs through PANoptosome complexes, has been implicated in the pathology of viral infections. Therefore, understanding the molecular mechanisms regulating PANoptosis in response to β-CoV infection is critical for identifying new therapeutic targets that can mitigate disease severity. In the current study, we analyzed findings from a cell death-based CRISPR screen with archetypal β-CoV mouse hepatitis virus (MHV) as the trigger to characterize host molecules required for inflammatory cell death. As a result, we identified SMARCA4, a chromatin regulator, as a putative host factor required for PANoptosis in response to MHV. Furthermore, we observed that gRNA-mediated deletion of Smarca4 inhibited MHV-induced PANoptotic cell death in macrophages. These findings have potential translational and clinical implications for the advancement of treatment strategies for β-CoVs and other infections. [ABSTRACT FROM AUTHOR]

Aims: Osteosarcoma is the most common primary bone malignancy among children and adolescents. We investigated whether benzamil, an amiloride analogue and sodium-calcium exchange blocker, may exhibit therapeutic potential for osteosarcoma in vitro. Methods: MG63 and U2OS cells were treated with benzamil for 24 hours. Cell viability was evaluated with the MTS/PMS assay, colony formation assay, and flow cytometry (forward/side scatter). Chromosome condensation, the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay, cleavage of poly-ADP ribose polymerase (PARP) and caspase-7, and FITC annexin V/PI double staining were monitored as indicators of apoptosis. Intracellular calcium was detected by flow cytometry with Fluo-4 AM. The phosphorylation and activation of focal adhesion kinase (FAK) and signal transducer and activator of transcription 3 (STAT3) were measured by western blot. The expression levels of X-linked inhibitor of apoptosis protein (XIAP), B-cell lymphoma 2 (Bcl-2), B-cell lymphoma-extra large (Bcl-xL), SOD1, and SOD2 were also assessed by western blot. Mitochondrial status was assessed with tetramethylrhodamine, ethyl ester (TMRE), and intracellular adenosine triphosphate (ATP) was measured with BioTracker ATP-Red Live Cell Dye. Total cellular integrin levels were evaluated by western blot, and the expression of cell surface integrins was assessed using fluorescent-labelled antibodies and flow cytometry. Results: Benzamil suppressed growth of osteosarcoma cells by inducing apoptosis. Benzamil reduced the expression of cell surface integrins α5, αV, and β1 in MG63 cells, while it only reduced the expression of αV in U2OS cells. Benzamil suppressed the phosphorylation and activation of FAK and STAT3. In addition, mitochondrial function and ATP production were compromised by benzamil. The levels of anti-apoptotic proteins XIAP, Bcl-2, and Bcl-xL were reduced by benzamil. Correspondingly, benzamil potentiated cisplatin- and methotrexate-induced apoptosis in osteosarcoma cells. Conclusion: Benzamil exerts anti-osteosarcoma activity by inducing apoptosis. In terms of mechanism, benzamil appears to inhibit integrin/FAK/STAT3 signalling, which triggers mitochondrial dysfunction and ATP depletion. Cite this article: Bone Joint Res 2024;13(4):157–168.

Ischemic-reperfusion injury limits the time window of recanalization therapy in cerebral acute ischemic stroke (AIS). Brain vessel endothelial cells (BVECs) form the first layer of the blood–brain barrier (BBB) and are thus the first sufferer of ischemic-reperfusion disorder. The current study demonstrates that melatonin can reduce infarct volume, alleviate brain edema, ameliorate neurological deficits, and protect BBB integrity in prolonged-stroke mice. Here, we demonstrate that endoplasmic reticulum (ER)–associated injury contributes to BVEC death in the dural phase of reperfusion after prolonged ischemia. When encountering ischemia, ER stress arises, specifically activating PERK-EIF2α signaling and the subsequent programmed cell death. Prolonged ischemia leads stress granules (SGs) to be refractory, which remain unresolved and accumulate in ER during recanalization. During reperfusion, refractory SGs activate PKR-EIF2α and further exacerbate BVEC injury. We report that melatonin treatment downregulates ER stress in the ischemic period and enhances dissociation of the refractory SGs during reperfusion, thus offering dual-phase protection to BVECs in prolonged cerebral stroke. Mechanistically, melatonin enhances autophagy in BVECs, which preserves ER function and resolves refractory SGs. We, therefore, propose that melatonin is a potential treatment to extend the time window of delayed recanalization therapy in AIS. [ABSTRACT FROM AUTHOR]

Background: 8-hydroxydaidzein (8-OHD) is a compound derived from daidzein, known for its anti-inflammatory and anti-proliferative properties in K562 human chronic myeloid leukemia (CML) cells. However, its effects on acute myeloid leukemia (AML) cells have not been fully understood. Method: To investigate its potential anti-AML mechanism, we employed an integrated in vitro–in silico approach. Results: Our findings demonstrate that 8-OHD suppresses the expression of CDK6 and CCND2 proteins and induces cell apoptosis in U-937 cells by activating Caspase-7 and cleaving PARP-1. Microarray analysis revealed that 8-OHD downregulates differentially expressed genes (DEGs) associated with rRNA processing and ribosome biogenesis pathways. Moreover, AML-target genes, including CCND2, MYC, NPM1, FLT3, and TERT, were downregulated by 8-OHD. Additionally, molecular docking software predicted that 8-OHD has the potential to interact with CDK6, FLT3, and TERT proteins, thereby reducing their activity and inhibiting cell proliferation. Notably, we discovered a synergic pharmacological interaction between 8-OHD and cytarabine (Ara-C). Conclusions: Overall, this study provides insights into the therapeutic applications of 8-OHD in treating AML and elucidates its underlying mechanisms of action. [ABSTRACT FROM AUTHOR]

During regulated cell death, apparently contradictory events occur: cells simultaneously activate death-accelerating and death-delaying pathways. Meanwhile, dying cells undertake other activities, specific effector programs (e.g., epithelial cell extrusion or cytokine processing), that are not directly related to living or dying. Here, we propose that specific effector programs are 'bucket lists' that need to be accomplished before the cell dies. For example, intestinal epithelial cells need to complete the extrusion bucket lists before they die. Likewise, macrophages that activate caspase 1 must process IL-1β/IL-18 before they undergo pyroptosis. To complete bucket lists, cells activate death-delaying pathways that repair membrane pores. If a cell dies prematurely, then it will fail to complete these bucket lists, resulting in pathological consequences. Regulated cell death occurs in many forms, including apoptosis, pyroptosis, necroptosis, and NETosis. Most obviously, the purpose of these pathways is to kill the cell. However, many cells need to complete a set of effector programs before they die, which we define as a cellular 'bucket list'. These effector programs are specific to the cell type, and mode and circumstances of death. For example, intestinal epithelial cells need to complete the process of extrusion before they die. Cells use regulatory mechanisms to temporarily prolong their life, including endosomal sorting complex required for transport (ESCRT)- and acid sphingomyelinase (ASM)-driven membrane repair. These allow cells to complete their bucket lists before they die. [ABSTRACT FROM AUTHOR]

Performing aerobic exercise in different disease conditions can regulate cardiac homeostasis and reduce cardiac apoptosis caused by the disease. In brain cancer, other tissues, including cardiac tissue, can also be affected. Since exercise training causes organ crosstalk, in this study, the effects of aerobic exercise training (AET) on cardiac apoptosis in Glioblastoma multiforme (GBM) rats are evaluated. Twenty-four male Wistar rats were divided into 3 groups (n=8 in each) of healthy control, GBM, and GBM+AET. Glioblastoma was injected into the frontal cortex of rats. The training group (AET) performed aerobic exercises on the treadmill for 4 weeks, 3 days a week at a speed of 18 meters per minute, for 25-40 minutes. In the end, the rats were sacrificed and caspase-3 and caspase-7 were analyzed from the myocardium by Real-time PCR method. Considering H&E image, the GBM group showed necrosis and apoptosis in cardiac tissue compared to the healthy group. Compared to the healthy control group, GBM significantly increased caspase-3 and caspase-7 mRNA in the myocardium (p

Abstract Background Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and has an extremely poor prognosis. We aimed to determine the latent relationships between TRIM36 regulation of apoptosis and the Wnt/β-catenin pathway in HCC. Methods Immunohistochemistry and western blotting were used to characterize the aberrant expression of TRIM36 in HCC and adjacent tissues. Clinical information was analyzed using Kaplan–Meier and Cox methods. RNA-seq of potential targets was conducted to detect the regulation of TRIM36. Apoptosis assays and cellular proliferation, invasion and migration were conducted in a loss- and gain-of-function manner in cultured cells to determine the biological functions of TRIM36. A rescue experiment was conducted to confirm the role of Wnt/β-catenin signaling in TRIM36 regulation. Finally, in vivo experiments were conducted using cell line-derived xenografts in nude mice to validate the central role of TRIM36 in HCC. Results TRIM36 expression was significantly downregulated in HCC tissues compared to adjacent non-tumor tissues. TRIM36 repressed the proliferation, migration, and invasion of Huh7 and HCCLM3 cells, whereas it stimulated apoptosis. Wnt/β-catenin signaling was inhibited by TRIM36, and rescue experiments highlighted its importance in HCC proliferation, migration, and invasion. In vivo experiments further confirmed the effects of sh-TRIM36 on HCC tumorigenesis, inhibition of apoptosis, and promotion of Wnt/β-catenin signaling. Conclusion Our study is the first to indicate that TRIM36 acts as a tumor suppressor in HCC. TRIM36 activates apoptosis and inhibits cellular proliferation, invasion, and migration via the Wnt/β-catenin pathway, which may serve as an important biomarker and promising therapeutic target for HCC.

Gasdermin (GSDM)-mediated cell death is an ancient immune defensive mechanism that plays an essential role in bacteria, fungi, coral, teleost, and mammals. After being cleaved by proteases of hosts or pathogens, aminoterminal (NT) fragment of GSDMs (GSDM-NTs) form pores in the membrane structure of cells, thereby leading to pyroptotic cell death. However, the expression profile, activation mechanism and function of avian GSDMs have not been studied in depth yet. In the current study, genes encoding duck gasdermin E (duGSDME), caspase-3 (ducaspase-3) and ducaspase-7 were cloned from mRNA of a virus-challenged duck embryo. The cleavage of duGSDME by ducaspase-3/-7 was verified in the cell-free system and/or in human embryonic kidney cells (HEK293). Ducaspase-3/-7 could recognize and cleave duGSDME at 270DAVD273. Overexpression of duGSDME-NT (1-273aa) fragment led to pyroptosis-like morphological change, increased lactic dehydrogenase (LDH) release and propidium iodide uptake of HEK293 cells, which indicated that duGSDME-NTs could cause cell membrane damage. In addition, recombinantly expressed duGSDME-NT showed bactericidal activity to an enterotoxic Escherichia coli (F5+) strain. The expression level of duGSDME was low in duckling tissues. DHAV-3 challenge upregulated the expression of duGSDME and ducaspase-3 in different tissues and led to the activation of ducaspase-3 and cleavage of duGSDME. The results indicated that duGSDME is a substrate of ducapsase-3/-7, and duGSDME-NT can cause pyroptosis. In addition, duGSDME may play a role in the immune defense of ducks against infectious diseases after being cleaved by ducaspase-3. The current study provides essential information for further investigation of the mechanisms of avian innate immunity and avian diseases. [ABSTRACT FROM AUTHOR]

Therapy resistance is still a major reason for treatment failure in colorectal cancer (CRC). Previously, we identified the E3 ubiquitin ligase TRIM25 as a novel suppressor of caspase-2 translation which contributes to the apoptosis resistance of CRC cells towards chemotherapeutic drugs. Here, we report the executioner caspase-7 as being a further target of TRIM25. The results from the gain- and loss-of-function approaches and the actinomycin D experiments indicate that TRIM25 attenuates caspase-7 expression mainly through a decrease in mRNA stability. The data from the RNA pulldown assays with immunoprecipitated TRIM25 truncations indicate a direct TRIM25 binding to caspase-7 mRNA, which is mediated by the PRY/SPRY domain, which is also known to be highly relevant for protein–protein interactions. By employing TRIM25 immunoprecipitation, we identified the heterogeneous nuclear ribonucleoprotein H1 (hnRNPH1) as a novel TRIM25 binding protein with a functional impact on caspase-7 mRNA stability. Notably, the interaction of both proteins was highly sensitive to RNase A treatment and again depended on the PRY/SPRY domain, thus indicating an indirect interaction of both proteins which is achieved through a common RNA binding. Ubiquitin affinity chromatography showed that both proteins are targets of ubiquitin modification. Functionally, the ectopic expression of caspase-7 in CRC cells caused an increase in poly ADP-ribose polymerase (PARP) cleavage concomitant with a significant increase in apoptosis. Collectively, the negative regulation of caspase-7 by TRIM25, which is possibly executed by hnRNPH1, implies a novel survival mechanism underlying the chemotherapeutic drug resistance of CRC cells. The targeting of TRIM25 could therefore offer a promising strategy for the reduction in therapy resistance in CRC patients. [ABSTRACT FROM AUTHOR]

Programmed cell death (PCD) is an important mechanism of innate immunity against bacterial pathogens. The innate immune PCD pathway involves the molecules caspase-7 and caspase-8, among others. Brucella abortus is a gram-negative bacterium that causes a zoonotic disease termed brucellosis. The innate immune response against this pathogen involves activation of inflammasome components and induction of pyroptosis. However, no studies so far have revealed the role of caspase-7 or caspase-8 during this bacterial infection. Herein, we demonstrate that caspase-7 is dispensable for caspase-1 processing, IL-1β secretion and cell death in macrophages. Additionally, caspase-7 deficient animals control B. abortus infection as well as the wild type mice. Furthermore, we addressed the role of caspase-8 in inflammasome activation and pyroptosis during this bacterial infection. Macrophages deficient in caspase-8 secreted reduced amounts of IL-1β that parallels with diminished caspase-1 activity when compared to wild type cells. Additionally, caspase-8 KO macrophages showed reduced LDH release when compared to wild type, suggesting that caspase-8 may play an important role in pyroptosis in response to B. abortus. Finally, caspase-8 KO animals were more susceptible to Brucella infection when compared to wild type mice. Overall, this study contributes to a better understanding of the involvement of caspase-7 and caspase-8 in innate immunity against B. abortus infection. [ABSTRACT FROM AUTHOR]

Background: 8-hydroxydaidzein (8-OHD) is a compound derived from daidzein, known for its anti-inflammatory and anti-proliferative properties in K562 human chronic myeloid leukemia (CML) cells. However, its effects on acute myeloid leukemia (AML) cells have not been fully understood. Method: To investigate its potential anti-AML mechanism, we employed an integrated in vitro–in silico approach. Results: Our findings demonstrate that 8-OHD suppresses the expression of CDK6 and CCND2 proteins and induces cell apoptosis in U-937 cells by activating Caspase-7 and cleaving PARP-1. Microarray analysis revealed that 8-OHD downregulates differentially expressed genes (DEGs) associated with rRNA processing and ribosome biogenesis pathways. Moreover, AML-target genes, including CCND2, MYC, NPM1, FLT3, and TERT, were downregulated by 8-OHD. Additionally, molecular docking software predicted that 8-OHD has the potential to interact with CDK6, FLT3, and TERT proteins, thereby reducing their activity and inhibiting cell proliferation. Notably, we discovered a synergic pharmacological interaction between 8-OHD and cytarabine (Ara-C). Conclusions: Overall, this study provides insights into the therapeutic applications of 8-OHD in treating AML and elucidates its underlying mechanisms of action.

Abstract Background We have previously reported that the free fatty acid extract (FFAE) of krill oil (KO) significantly inhibits the proliferation and migration, and induces apoptosis of colorectal cancer (CRC) cells. This study aimed to investigate the in vivo efficacy of various doses of KO supplementation on the inhibition of CRC tumour growth, molecular markers of proliferation, angiogenesis, apoptosis, the epidermal growth factor receptor (EGFR) and its downstream molecular signalling. Methods Male Balb/c mice were randomly divided into four groups with five in each group. The control (untreated) group received standard chow diet; and other three groups received KO supplementation at 5%, 10%, and 15% of their daily dietary intake respectively for three weeks before and after the orthotopic implantation of CT-26 CRC cells in their caecum. The expression of cell proliferation marker Ki-67 and angiogenesis marker CD-31 were assessed by immunohistochemistry. The expression of EGFR, phosphorylated EGFR (pEGFR), protein kinase B (AKT), pAKT, extracellular signal-regulated kinase (ERK1/2), pERK1/2, cleaved caspase-7, cleaved poly (ADP-ribose) polymerase (PARP), and DNA/RNA damage were determined by western blot. Results KO supplementation reduced the CRC tumour growth in a dose-dependent manner; with 15% of KO being the most effective in reduction of tumour weight and volume (68.5% and 68.3% respectively, P

Abstract Background Chinese hamster ovary cell line has been used routinely as a bioproduction factory of numerous biopharmaceuticals. So far, various engineering strategies have been recruited to improve the production efficiency of this cell line such as apoptosis engineering. Previously, it is reported that the caspase-7 deficiency in CHO cells reduces the cell proliferation rate. But the effect of this reduction on the CHO cell productivity remained unclear. Hence, in the study at hand the effect of caspase-7 deficiency was assessed on the cell growth, viability and protein expression. In addition, the enzymatic activity of caspase-3 was investigated in the absence of caspase-7. Results Findings showed that in the absence of caspase-7, both cell growth and cell viability were decreased. Cell cycle analysis illustrated that the CHO knockout (CHO-KO) cells experienced a cell cycle arrest in G2/M phase. This cell cycle arrest resulted in a 1.7-fold increase in the expression of luciferase in CHO-KO cells compared to parenteral cells. Furthermore, in the apoptotic situation the enzymatic activity of caspase-3 in CHO-KO cells was approximately 3 times more than CHO-K1 cells. Conclusions These findings represented that; however, caspase-7 deficiency reduces the cell proliferation rate but the resulted cell cycle arrest leads to the enhancement of recombinant protein expression. Moreover, increasing in the caspase-3 enzymatic activity compensates the absence of caspase-7 in the caspase cascade of apoptosis.

Programmed cell death (PCD) is an important mechanism of innate immunity against bacterial pathogens. The innate immune PCD pathway involves the molecules caspase-7 and caspase-8, among others. Brucella abortus is a gram-negative bacterium that causes a zoonotic disease termed brucellosis. The innate immune response against this pathogen involves activation of inflammasome components and induction of pyroptosis. However, no studies so far have revealed the role of caspase-7 or caspase-8 during this bacterial infection. Herein, we demonstrate that caspase-7 is dispensable for caspase-1 processing, IL-1β secretion and cell death in macrophages. Additionally, caspase-7 deficient animals control B. abortus infection as well as the wild type mice. Furthermore, we addressed the role of caspase-8 in inflammasome activation and pyroptosis during this bacterial infection. Macrophages deficient in caspase-8 secreted reduced amounts of IL-1β that parallels with diminished caspase-1 activity when compared to wild type cells. Additionally, caspase-8 KO macrophages showed reduced LDH release when compared to wild type, suggesting that caspase-8 may play an important role in pyroptosis in response to B. abortus. Finally, caspase-8 KO animals were more susceptible to Brucella infection when compared to wild type mice. Overall, this study contributes to a better understanding of the involvement of caspase-7 and caspase-8 in innate immunity against B. abortus infection.

Background: Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and has an extremely poor prognosis. We aimed to determine the latent relationships between TRIM36 regulation of apoptosis and the Wnt/β-catenin pathway in HCC. Methods: Immunohistochemistry and western blotting were used to characterize the aberrant expression of TRIM36 in HCC and adjacent tissues. Clinical information was analyzed using Kaplan–Meier and Cox methods. RNA-seq of potential targets was conducted to detect the regulation of TRIM36. Apoptosis assays and cellular proliferation, invasion and migration were conducted in a loss- and gain-of-function manner in cultured cells to determine the biological functions of TRIM36. A rescue experiment was conducted to confirm the role of Wnt/β-catenin signaling in TRIM36 regulation. Finally, in vivo experiments were conducted using cell line-derived xenografts in nude mice to validate the central role of TRIM36 in HCC. Results: TRIM36 expression was significantly downregulated in HCC tissues compared to adjacent non-tumor tissues. TRIM36 repressed the proliferation, migration, and invasion of Huh7 and HCCLM3 cells, whereas it stimulated apoptosis. Wnt/β-catenin signaling was inhibited by TRIM36, and rescue experiments highlighted its importance in HCC proliferation, migration, and invasion. In vivo experiments further confirmed the effects of sh-TRIM36 on HCC tumorigenesis, inhibition of apoptosis, and promotion of Wnt/β-catenin signaling. Conclusion: Our study is the first to indicate that TRIM36 acts as a tumor suppressor in HCC. TRIM36 activates apoptosis and inhibits cellular proliferation, invasion, and migration via the Wnt/β-catenin pathway, which may serve as an important biomarker and promising therapeutic target for HCC. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a neurodegenerative disorder molecularly characterized by the formation of amyloid β (Aβ) plaques and type 2 microtubule-associated protein (Tau) abnormalities. Multiple studies have shown that many of the brain's immunological cells, specifically microglia and astrocytes, are involved in AD pathogenesis. Cells of the innate immune system play an essential role in eliminating pathogens but also regulate brain homeostasis and AD. When activated, innate immune cells can cause programmed cell death through multiple pathways, including pyroptosis, apoptosis, necroptosis, and PANoptosis. The cell death often results in the release of proinflammatory cytokines that propagate the innate immune response and can eliminate Aβ plaques and aggregated Tau proteins. However, chronic neuroinflammation, which can result from cell death, has been linked to neurodegenerative diseases and can worsen AD. Therefore, the innate immune response must be tightly balanced to appropriately clear these AD-related structural abnormalities without inducing chronic neuroinflammation. In this review, we discuss neuroinflammation, innate immune responses, inflammatory cell death pathways, and cytokine secretion as they relate to AD. Therapeutic strategies targeting these innate immune cell death mechanisms will be critical to consider for future preventive or palliative treatments for AD. [ABSTRACT FROM AUTHOR]

The innate immune system provides the first line of defense against cellular perturbations. Innate immune activation elicits inflammatory programmed cell death in response to microbial infections or alterations in cellular homeostasis. Among the most well-characterized programmed cell death pathways are pyroptosis, apoptosis, and necroptosis. While these pathways have historically been defined as segregated and independent processes, mounting evidence shows significant crosstalk among them. These molecular interactions have been described as 'crosstalk', 'plasticity', 'redundancies', 'molecular switches', and more. Here, we discuss the key components of cell death pathways and note several examples of crosstalk. We then explain how the diverse descriptions of crosstalk throughout the literature can be interpreted through the lens of an integrated inflammatory cell death concept, PANoptosis. The totality of biological effects in PANoptosis cannot be individually accounted for by pyroptosis, apoptosis, or necroptosis alone. We also discuss PANoptosomes, which are multifaceted macromolecular complexes that regulate PANoptosis. We consider the evidence for PANoptosis, which has been mechanistically characterized during influenza A virus, herpes simplex virus 1, Francisella novicida, and Yersinia infections, as well as in response to altered cellular homeostasis, in inflammatory diseases, and in cancers. We further discuss the role of IRF1 as an upstream regulator of PANoptosis and conclude by reexamining historical studies which lend credence to the PANoptosis concept. Cell death has been shown to play a critical role in infections, inflammatory diseases, neurodegenerative diseases, cancers, and more; therefore, having a holistic understanding of cell death is important for identifying new therapeutic strategies. [ABSTRACT FROM AUTHOR]

Background: We have previously reported that the free fatty acid extract (FFAE) of krill oil (KO) significantly inhibits the proliferation and migration, and induces apoptosis of colorectal cancer (CRC) cells. This study aimed to investigate the in vivo efficacy of various doses of KO supplementation on the inhibition of CRC tumour growth, molecular markers of proliferation, angiogenesis, apoptosis, the epidermal growth factor receptor (EGFR) and its downstream molecular signalling. Methods: Male Balb/c mice were randomly divided into four groups with five in each group. The control (untreated) group received standard chow diet; and other three groups received KO supplementation at 5%, 10%, and 15% of their daily dietary intake respectively for three weeks before and after the orthotopic implantation of CT-26 CRC cells in their caecum. The expression of cell proliferation marker Ki-67 and angiogenesis marker CD-31 were assessed by immunohistochemistry. The expression of EGFR, phosphorylated EGFR (pEGFR), protein kinase B (AKT), pAKT, extracellular signal-regulated kinase (ERK1/2), pERK1/2, cleaved caspase-7, cleaved poly (ADP-ribose) polymerase (PARP), and DNA/RNA damage were determined by western blot. Results: KO supplementation reduced the CRC tumour growth in a dose-dependent manner; with 15% of KO being the most effective in reduction of tumour weight and volume (68.5% and 68.3% respectively, P < 0.001), inhibition of cell proliferation by 69.9% (P < 0.001) and microvessel density by 72.7% (P < 0.001). The suppressive effects of KO on EGFR and its downstream signalling, ERK1/2 and AKT, were consistent with our previous in vitro observations. Furthermore, KO exhibited pro-apoptotic effects on tumour cells as indicated by an increase in the expression of cleaved PARP by 3.9-fold and caspase-7 by 8.9-fold. Conclusions: This study has demonstrated that KO supplementation reduces CRC tumour growth by inhibiting cancer cell proliferation and blood vessel formation and inducing apoptosis of tumour cells. These anti-cancer effects are associated with the downregulation of the EGFR signalling pathway and activation of caspase-7, PARP cleavage, and DNA/RNA damage. [ABSTRACT FROM AUTHOR]

Background: Chinese hamster ovary cell line has been used routinely as a bioproduction factory of numerous biopharmaceuticals. So far, various engineering strategies have been recruited to improve the production efficiency of this cell line such as apoptosis engineering. Previously, it is reported that the caspase-7 deficiency in CHO cells reduces the cell proliferation rate. But the effect of this reduction on the CHO cell productivity remained unclear. Hence, in the study at hand the effect of caspase-7 deficiency was assessed on the cell growth, viability and protein expression. In addition, the enzymatic activity of caspase-3 was investigated in the absence of caspase-7. Results: Findings showed that in the absence of caspase-7, both cell growth and cell viability were decreased. Cell cycle analysis illustrated that the CHO knockout (CHO-KO) cells experienced a cell cycle arrest in G2/M phase. This cell cycle arrest resulted in a 1.7-fold increase in the expression of luciferase in CHO-KO cells compared to parenteral cells. Furthermore, in the apoptotic situation the enzymatic activity of caspase-3 in CHO-KO cells was approximately 3 times more than CHO-K1 cells. Conclusions: These findings represented that; however, caspase-7 deficiency reduces the cell proliferation rate but the resulted cell cycle arrest leads to the enhancement of recombinant protein expression. Moreover, increasing in the caspase-3 enzymatic activity compensates the absence of caspase-7 in the caspase cascade of apoptosis. [ABSTRACT FROM AUTHOR]

Therapy resistance is still a major reason for treatment failure in colorectal cancer (CRC). Previously, we identified the E3 ubiquitin ligase TRIM25 as a novel suppressor of caspase-2 translation which contributes to the apoptosis resistance of CRC cells towards chemotherapeutic drugs. Here, we report the executioner caspase-7 as being a further target of TRIM25. The results from the gain- and loss-of-function approaches and the actinomycin D experiments indicate that TRIM25 attenuates caspase-7 expression mainly through a decrease in mRNA stability. The data from the RNA pulldown assays with immunoprecipitated TRIM25 truncations indicate a direct TRIM25 binding to caspase-7 mRNA, which is mediated by the PRY/SPRY domain, which is also known to be highly relevant for protein–protein interactions. By employing TRIM25 immunoprecipitation, we identified the heterogeneous nuclear ribonucleoprotein H1 (hnRNPH1) as a novel TRIM25 binding protein with a functional impact on caspase-7 mRNA stability. Notably, the interaction of both proteins was highly sensitive to RNase A treatment and again depended on the PRY/SPRY domain, thus indicating an indirect interaction of both proteins which is achieved through a common RNA binding. Ubiquitin affinity chromatography showed that both proteins are targets of ubiquitin modification. Functionally, the ectopic expression of caspase-7 in CRC cells caused an increase in poly ADP-ribose polymerase (PARP) cleavage concomitant with a significant increase in apoptosis. Collectively, the negative regulation of caspase-7 by TRIM25, which is possibly executed by hnRNPH1, implies a novel survival mechanism underlying the chemotherapeutic drug resistance of CRC cells. The targeting of TRIM25 could therefore offer a promising strategy for the reduction in therapy resistance in CRC patients.

Chronic obstructive pulmonary disease (COPD) and essential hypertension (EH) are one of the most common, leading and current problems of practical public health. The purpose of this study was to evaluate the clinical efficacy of the metabolic correction agent (“Tivortin”) in the complex treatment of patients with COPD in the presence of EH. Materials and methods. We examined 23 patients with the diagnosis of EH stage II and COPD stage II as the main group, mean age 51.72 ± 1.22; various cardiovascular risk, without adequate systematic antihypertensive therapy; disease duration – 7.52 ± 1.14; 82.6 % – active smokers, pack-years index – 17.23 ± 2.69. All patients of the main group took L-arginine aspartate in the form of a 4.2 % solution intravenously, 100 ml 1 time per day (course of 10–12 days) with the subsequent transfer to the solution for oral administration of 10 ml 5 times a day (course of 3 months ± 3 days). The comparison group (n = 15, age 49.15 ± 1.40), comparable in clinical and demographic parameters to the main group, was also studied (initially and after 3 months) and received similar traditional therapy for EH and COPD without the use of a metabolite drug – exogenous L-arginine “Tivortin”. Diagnosis of COPD and hypertension was carried out on the basis of generally accepted criteria. The quality of life (QOL) parameters were assessed according to the SF-36 “Short Health Assessment Questionnaire”. The metabolism of glutathione and the state of the thiol-disulfide balance was studied by the content of oxidized and reduced glutathione and the activity of the enzymes glutathione-S-transferase, glutathione reductase and glutathione peroxidase in the blood serum. The content of ST2, CASPASE-7 and CASPASE-9 in the blood was determined using the appropriate ELISA test systems. Results. The administration of L-arginine contributed to the suppression of oxidative stress and the restoration of the thiol-disulfide balance and, as a result of the above processes, inhibited the apoptosis in the body of patients with comorbidity. The expression level of ST2 protein after treatment of patients with EH and COPD by “Tivortin” decreased by half, and the compensatory ability of the patient body, which is to enable the cardioprotective signaling cascade to prevent fibrosis and remodeling of the heart in the most optimal way, will be realized after the experimental treatment. In addition to the regression of clinical symptoms, normalization of blood pressure and improvement of bronchial patency against the background of a decrease in the level of activity of apoptotic markers, there is a restoration of the quality of life, both physical and psychosocial status. Conclusions. The additional use of L-arginine against the background of conventional therapy with COPD and EH promotes more significant and reliable suppression of oxidative stress and restores thiol-disulphide balance and, as a result of the above-mentioned processes, inhibits the intensification of apoptosis in patients with this comorbidity. In addition to regression of clinical symptoms, normalization of blood pressure and improvement of bronchial patency on the background of lowering the activity of apoptotic markers, there is a significant recovery of QOL, both physical and psychosocial status.

Diabetes contributes to neurological dysfunction including peripheral nerve diseases, stroke and dementia. We investigated the effects of diabetes on apoptosis and mitosis in the hippocampal CA1 region. Rats were given diabetes by injection of streptozotocin (STZ). The mass and blood glucose levels of the rats were measured until day 7 of the experiment. The loss of mass index was approximately 10%, and the diabetogenic index was approximately 330% between nondiabetic and diabetic groups. We investigated caspase-3, caspase-7 and Ki 67 levels immunohistochemically for mitotic activity, the TUNEL method for apoptosis and GFAP for astrocyte cell density in the hippocampal CA1 region. We found that apoptotic cells and the number of astrocytes and mitotic activity in the diabetic group were increased significantly compared to controls. Diabetes stimulates apoptosis and promotes cell proliferation in the hippocampal CA1 region, which may impair its homeostasis and function. [ABSTRACT FROM AUTHOR]

Aim. Determine the activity of apoptosis processes in young children with anemia of inflammation acquired on the background of acute bacterial diseases of respiratory organs. Material and methods. The content of caspase-7 and caspase-9 was identified in blood serum of 87 kids by the method of immunoenzyme assay. Main group included 57 kids with acute bacterial diseases of the respiratory tract (38 patients had acute bacterial bronchitis, 19 - pneumonia). The main group was divided into two subgroups. The first subgroup included 27 children with developed anemia of inflammation acquired on the background of acute bacterial disease of the respiratory tract. Second subgroup - 30 children with acute bacterial diseases of the respiratory tract without anemia. Experimental group - 10 children with iron deficiency anemia without symptoms of inflammatory diseases of the respiratory system. The control group was represented by 20 conditionally healthy children. Results. The presence of pneumonia in children was accompanied by the highest numbers of caspase-9 (14.8 ± 1.8 ng/ml), which was almost 3 times higher than the control group (5.82 ± 0.58 ng/ml). The levels of the studied enzyme were 1.6 times lower in patients with bacterial bronchitis (8.34 ± 0.90 ng/ml), which was significantly higher (P < 0.05) than in the control group. The content of caspase-7 in the experimental group and the 2nd subgroup of the main group did not differ from the control group (P > 0.05) (0.38 ± 0.03 ng/ml and 0.32 ± 0.02 ng/ml), and children of the 1st subgroup (0.27 ± 0.02 ng/ml) showed its significant decrease. Conclusions. Anemia of inflammation in children with acute bacterial diseases of respiratory organs is accompanied by the activation of apoptosis, which, obviously, is inefficient due to the nature of the active necrotic processes acquired on the background of acute inflammation.

Objective: To analize the effect of resveratrol to the expression of caspase-7 and density of retinal ganglion cells in a rat model with Traumatic Optic Neuropathy (TON) compared to control. Methods: This is an experimental study using Wistar rats. Samples were divided into four groups. One normal control group, 1 TON control group and 2 TON resveratrol groups. TON induced by clamping the optic nerve retrobulbar with Hartmann Mosquito 2,5 inch. Resveratrol was given 10 mg/Kg and 20 mg/Kg in two resveratrol groups. Enucleation was performed 1 day after to evaluate the expression of Caspase-7 by immunohistochemistry and density of retinal ganglion cell by hematoxicilin eosin staining. Results: Caspase-7 expression was lowest in the resveratrol 20 mg/kg treatment group (4.00 ± 2.00) compared to resveratrol 10 mg/kg treatment group (6.00±2.23), TON control group(6.00 ± 6.78) and normal control group(7.20 ± 2.58). Retinal ganglion cell density was highest in the resveratrol 10 mg/kg treatment group (27.23±2.75) compared to resveratrol 20 mg/kg treatment group (24.89±5.83), normal control group(24.19±2.39) and the lowest in TON control group (22.96±4.62). Based on the Pearson correlation test, it was found that there was no correlation between Caspase-7 expression and retinal ganglion cell density in a rat model with TON (p: 0.178; r = 0.314) Conclusions: Resveratrol administration shows effect in lowering apoptosis marker caspase-7 and preserving retinal ganglion cell in traumatic optic neuropathy. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the direct antitumor activity of edible fungal polysaccharide Lentinan, rather than as a host defence potentiator, on human breast cancer and investigate its underlying mechanisms. The present results revealed that there were 45.46% and 59.16% of inhibitory rate after Lentinan treatment in MCF-7 cells and tumor-bearing athymic nude mice, respectively. Annexin V-FITC/PI, H&E staining and TUNEL assay showed that Lentinan induced cell apoptosis which accompanied with abundant activated caspase-7, increased cytosol cytochrome c and Bax/Bcl-2. Unexpectedly, we firstly demonstrated that Lentinan could stimulate cell autophagy according to the detection of autophagosomes and autophagic flux. Pretreatment with autophagy inhibitors decreased Lentinan-induced cells death. These findings provided new insight into the mechanisms of Lentinan-antitumor effect and contributed to its development in functional foods and cancer therapy.

Inflammasomes are innate immune mechanisms that activate caspase‐1 in response to a variety of stimuli, including Salmonella infection. Active caspase‐1 has a potential to induce two different types of cell death, depending on the expression of the pyroptosis mediator gasdermin D (GSDMD); following caspase‐1 activation, GSDMD‐sufficient and GSDMD‐null/low cells undergo pyroptosis and apoptosis, respectively. Although Bid, a caspase‐1 substrate, plays a critical role in caspase‐1 induction of apoptosis in GSDMD‐null/low cells, an additional mechanism that mediates this cell death independently of Bid has also been suggested. This study investigated the Bid‐independent pathway of caspase‐1‐induced apoptosis. Caspase‐1 has been reported to process caspase‐6 and caspase‐7. Silencing of caspase‐7, but not caspase‐6, significantly reduced the activation of caspase‐3 induced by caspase‐1, which was activated by chemical dimerization, in GSDMD/Bid‐deficient cells. CRISPR/Cas9‐mediated depletion of caspase‐7 had the same effect on the caspase‐3 activation. Moreover, in the absence of GSDMD and Bid, caspase‐7 depletion reduced apoptosis induced by caspase‐1 activation. Caspase‐7 was activated following caspase‐1 activation independently of caspase‐3, suggesting that caspase‐7 acts downstream of caspase‐1 and upstream of caspase‐3. Salmonella induced the activation of caspase‐3 in GSDMD‐deficient macrophages, which relied partly on Bid and largely on caspase‐1. The caspase‐3 activation and apoptotic morphological changes seen in Salmonella‐infected GSDMD/Bid‐deficient macrophages were attenuated by caspase‐7 knockdown. These results suggest that in addition to Bid, caspase‐7 can also mediate caspase‐1‐induced apoptosis and provide mechanistic insights into inflammasome‐associated cell death that is one major effector mechanism of inflammasomes. [ABSTRACT FROM AUTHOR]

Xanthorrhizol ( 1 ) is known as the major terpenoid component of the rhizome of Curcuma xanthorrhiza and having some interesting biological activities. In this report, we synthesised five derivatives of 1 containing nitrogen-functional groups. Four of them are new synthesised compounds, including (R)-4-(3-(2-methyl-5-(6-methylhept-5-en-2-yl)phenoxy)propyl)morpholine ( 2 ), (R)-N-benzyl-3-(2-methyl-5-(6-methylhept-5-en-2-yl)phenoxy)propan-1-amine ( 3 ), (R)-6,7-dimethoxy-3-(3-(2-methyl-5-(6-methylhept-5-en-2-yl)phenoxy)propyl)quinazolin-4(3H)-one ( 4 ), and (R)-6-methyl-3-(6-methylhept-5-en-2-yl)-2-nitrophenol ( 5 ) groups. Meanwhile the other is the known compound, that is (R)-2-methyl-5-(6-methylhept-5-en-2-yl)-4-nitrophenol ( 6 ). The caspase-7 inhibitory activity of compounds 1-6 was evaluated as well. In comparison to other derivatives, compounds 5 and 6 exhibited higher activity. Consequently, compounds 5 and 6 may be a promising lead compound for further development as a caspase-7 inhibitor.

Hetarylfuroxans (4-(2-methylpyridin-5-yloxy)-3-phenylfuroxan (1), bis(1,2,4-oxadiazol- 3-yl)furoxan (2), and 4-amino-3-(indenotriazin-3-yl)furoxan (3)) exhibit in vitro cytotoxic activity against chronic myeloid leukemia K562 cells. All studied furoxans induce apoptosis in K562 cells. The experiments with activation of caspases-3 and -7 showed that furoxan 3 possessed the highest apoptosis-inducing capacity. The studied hetarylfuroxans were found to be the promising drug candidates for the treatment of chronic myeloid leukemia K562. [ABSTRACT FROM AUTHOR]

Background/Aims: Caspases, an evolutionary conserved family of aspartate-specific cystein proteases, play pivotal roles in apoptotic and inflammatory signaling. Thus far, 14 mammalian caspases are identified and categorized into 3 distinct sub-types: inflammatory caspases, apoptotic initiator and apoptotic executioner. Caspase-1 is an inflammatory caspase, while caspase-7 belongs to apoptotic executioner. The roles and association of these two distinct types of caspases in renal tubulointerstitial fibrosis (TIF) have not been well recognized. Methods: Caspase-1 inhibitor Z-YVAD-FMK and caspase-7 siRNA were used in tubular epithelial cell line NRK-52E (TECs) to test their effects on transforming growth factor-beta1 (TGF-β1) stimulation. In vivo, Unilateral ureteral obstruction (UUO) animal model was employed in wild-type (WT) and caspase-1 knock out (KO) (caspase-1-/-) mice. Results: In current study, we found that caspase-7 was obviously activated in cultured TECs stimulated by TGF-β1 and in UUO model of WT mice. While in UUO model of caspase-1 KO mice, the increased caspase-7 activation was suppressed significantly along with reduced trans-differentiation and minimized extracellular matrix (ECM) accumulation, as demonstrated by western blot, Masson trichrome staining and immunohistochemistry. In addition, pharmacological inhibition of caspase-1 dampened caspase-7 activation and TECs' transdifferentiation induced by TGF-β1 exposure, which was consistent with in vivo study. Notably, caspase-7 gene knock down by specific siRNA abrogated TGF-β1 driven TECs' trans-differentiation and reduced ECM accumulation. Conclusions: Our study associated inflammatory and apoptotic caspases in TIF for the first time and we further confirmed that caspase-1 activation is an upstream event of apoptotic caspase-7 induction in TIF triggered by UUO and in TECs mediated by TGF-β1 induced transdifferentiation.

The aim of this study was to evaluate the direct antitumor activity of edible fungal polysaccharide Lentinan, rather than as a host defence potentiator, on human breast cancer and investigate its underlying mechanisms. The present results revealed that there were 45.46% and 59.16% of inhibitory rate after Lentinan treatment in MCF-7 cells and tumor-bearing athymic nude mice, respectively. Annexin V-FITC/PI, H&E staining and TUNEL assay showed that Lentinan induced cell apoptosis which accompanied with abundant activated caspase-7, increased cytosol cytochrome c and Bax/Bcl-2. Unexpectedly, we firstly demonstrated that Lentinan could stimulate cell autophagy according to the detection of autophagosomes and autophagic flux. Pretreatment with autophagy inhibitors decreased Lentinan-induced cells death. These findings provided new insight into the mechanisms of Lentinan-antitumor effect and contributed to its development in functional foods and cancer therapy. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs), a critical part of the RNA silencing machinery, are known to play important regulatory roles in cancer. However, the consequence of miRNA deregulation in cancer is unknown for many miRNAs. Here, we define that miRNAs, miR-17-5p, miR-132-3p/-212-3p, and miR-337-3p are significantly up-regulated in the pancreatic ductal adenocarcinomas (PDAC) compared to the normal and benign tissues. Furthermore, by using PANC-1 cells, we demonstrate that overexpressed miR-337-3p and miR-17-5p/miR-132-3p/-212-3p can regulate executioner caspases-3 and -7, respectively. In addition, over-expression of miRNAs, especially miR-337-3p, attenuates tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) cytotoxicity in PANC-1 cells. Our findings unveil an important biological function for miRNAs up-regulated in PDAC in coordinately regulating caspases, potentially contributing to the malignant progression of PDAC. [ABSTRACT FROM AUTHOR]

Purpose: To investigate associations between gene expression pattern of apoptotic biomarkers in cumulus cells of polycystic ovary syndrome (PCOS) patients and the quality of oocytes and embryos.Methods: 40 intracytoplasmic sperm injection patients, of whom 20 were PCOS and 20 were healthy women, were included in this study. Serum hormone levels were measured using Radioimmunoassay for each patient. The expression of survivin, caspase-3, and caspase-7 in 200 cumulus complexes surrounding mature oocytes (100 in PCOS versus 100 in control groups) collected individually at pick up was examined by real-time polymerase chain reaction (real-time PCR).Results: The expression levels of survivin were significantly lower in PCOS patients than those of normal women while caspase-3 and caspase-7 expression levels were higher in PCOS patients (p < 0.05). There was a statistically significant correlation between the levels of these genes and embryo quality.Conclusions: This study reveals that the measurement of survivin, caspase-3, caspase-7 levels in cumulus cells of PCOS patients could be used as genetic biomarkers for oocyte and embryo selection under an ART program. However, further prospective studies are required to elucidate this issue. [ABSTRACT FROM AUTHOR]

The current study aimed to synthesize new metal coordination complexes with potential biomedical applications. Metal complexes were prepared via the reaction of isatin-N(4)anti- pyrinethiosemicarbazone ligand 1 with Cu(II), Ni(II), Co(II), Zn(II), and Fe(III) ions. The obtained metal complexes 2−12 were characterized using elemental, spectral (1H-NMR, EPR, Mass, IR, UV-Vis) and thermal (TGA) techniques, as well as magnetic moment and molar conductance measurements. In addition, their geometries were studied using EPR and UV−Vis spectroscopy. To evaluate the in vivo anti-cancer activities of these complexes, the ligand 1 and its metal complexes 2, 7 and 9 were tested against solid tumors. The solid tumors were induced by subcutaneous (SC) injection of Ehrlich ascites carcinoma (EAC) cells in mice. The impact of the selected complexes on the reduction of tumor volume was determined. Also, the expression levels of vascular endothelial growth factor (VEGF) and cysteine aspartyl-specific protease-7 (caspase-7) in tumor and liver tissues of mice bearing EAC tumor were determined. Moreover, their effects on alanine transaminase (ALT), aspartate transaminase (AST), albumin, and glucose levels were measured. The results revealed that the tested compounds, especially complex 9, reduced tumor volume, inhibited the expression of VEGF, and induced the expression of caspase-7. Additionally, they restored the levels of ALT, AST, albumin, and glucose close to their normal levels. Taken together, our newly synthesized metal complexes are promising anti-cancer agents against solid tumors induced by EAC cells as supported by the inhibition of VEGF and induction of caspase-7.

Contribution of individual BIR domains to Smac antagonism is investigated. Ammonium citrate was used to activate caspase-9 and pro-caspase-9 (D315, D330/A). However, the presence of citrate resulted in autoproteolysis of pro-caspase-9 and its inhibition by XIAP BIR3, which was not observed for apoptosome activated pro-caspase-9 indicating abnormal behavior of pro-caspase-9 in kosmotropic citrate salt. Thus, we used Apaf-1(residues 1-591) to activate caspase-9 through the formation of mini-apoptosome instead. Inhibition of apoptosome by XIAP BIR-1-2-3 was observed to be similar to that of BIR3 indicating that the cleavage of XIAP does not affect its potency. However, BIR1-2-3 was more prone to Smac antagonism due to simultaneous interaction of two BIR domains from XIAP with two N-terminal binding sites of Smac. Therefore, despite the role in caspase-9 activation, Apaf-1 does not influence caspase-9 inhibition by XIAP. In addition, caspase-3, -7 and -9 activity recovery by Smac protein and peptide were more efficient for BIR1-2-3 than for BIR1-2. Consequently, it can be proposed that the presence of multiple BIR domains for XIAP among different species along with dimeric nature of Smac are evolutionary designed to strengthen the antagonistic activity of Smac culminating in efficient induction of cell death. [ABSTRACT FROM AUTHOR]

Caspase family has been recognized to be involved in dopaminergic (DA) neuronal death and to exert an unfavorable role in Parkinson's disease (PD) pathology. Our previous study has revealed that caspase-1, as an important component of NLRP3 inflammasome, induces microglia-mediated neuroinflammation in the pathogenesis of PD. However, the role of caspase-1 in DA neuronal degeneration in the onset of PD remains unclear. Here, we showed that caspase-1 knockout ameliorated DA neuronal loss and dyskinesia in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine/probenecid (MPTP/p)-induced PD model mice. We further found that caspase-1 knockout decreased MPTP/p-induced caspase-7 cleavage, subsequently inhibited nuclear translocation of poly (ADP-ribose) polymerase 1 (PARP1), and reduced the release of apoptosis-inducing factor (AIF). Consistently, we demonstrated that caspase-1 inhibitor suppressed caspase-7/PARP1/AIF-mediated apoptosis pathway by 1-methyl-4-phenylpyridinium ion (MPP) stimulation in SH-SY5Y cells. Caspase-7 overexpression reduced the protective effects of caspase-1 inhibitor on SH-SY5Y cell apoptosis. Collectively, our results have revealed that caspase-1 regulates DA neuronal death in the pathogenesis of PD in mice via caspase-7/PARP1/AIF pathway. These findings will shed new insight into the potential of caspase-1 as a target for PD therapy. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the expression of caspase-3, caspase-7, caspase-9 and cytokeratin AE-1/AE-3 using the avidin-biotin complex (ABC) immunoperoxidase technique in 20 goats with enzootic nasal adenocarcinoma (ENA). Clinically, dyspnoea and nasal discharge were observed in all cases. Macroscopically, polypoid and sessile masses were seen in the ethmoidal area. At the histopathological examination, tubular, papillary and mixed patterns of ENA were diagnosed. Immunohistochemically, strong positive reactions were generally seen for caspase-3, while strong to moderate and slight reactions were observed for caspase-7 and caspase-9 in the cytoplasm of the tumour cells. Positive reactions for cytokeratin AE-1/AE-3 were only seen in epithelial cells. In addition, the causative agent of ENA, retrovirus, was detected immunohistochemically in tumour cells.

Ruviprase, a 4.4 kDa peptide isolated from Daboia russelii russelii venom demonstrated antiproliferative activity against EMT6/AR1, U-87MG, HeLa and MCF-7 cancer cells with an IC 50 value of 23.0, 8.8, 5.8 and 4.0 μg ml −1 , respectively. However, it was nontoxic to non-cancerous human embryonic kidney cell and human peripheral blood lymphocytes. Flow-cytometric analysis confirmed the apoptosis induction in MCF-7 cells by Ruviprase where it induced DNA condensation but did not cause mitotic blockage or chromosomal aberration in treated-cells. Immunofluorescence microscopic analysis indicated Ruviprase induced apoptosis in MCF-7 cells through p53 and p21-mediated pathways. Ruviprase generated reactive oxygen species (ROS), altered the mitochondrial transmembrane potential, and significantly decreased the cellular glutathione (GSH) content of MCF-7 cells. Immunoblotting and quantitative real-time PCR (qRT-PCR) analyses suggested that Ruviprase down-regulated the expression of anti-apoptotic protein Bcl-2, increased cleavage of poly (ADP-ribose) polymerase (PARP) protein, and up-regulated the expression of pro-apoptotic protein Bax, as well as executer protein caspase-7 to induced apoptosis in MCF-7 cells via intrinsic pathway. This is the first report on the characterization of the anticancer potential of a small, non-toxic and anticoagulant peptide purified from Russell's viper venom. [ABSTRACT FROM AUTHOR]

Background/Aims: Caspases, an evolutionary conserved family of aspartate-specific cystein proteases, play pivotal roles in apoptotic and inflammatory signaling. Thus far, 14 mammalian caspases are identified and categorized into 3 distinct sub-types: inflammatory caspases, apoptotic initiator and apoptotic executioner. Caspase-1 is an inflammatory caspase, while caspase-7 belongs to apoptotic executioner. The roles and association of these two distinct types of caspases in renal tubulointerstitial fibrosis (TIF) have not been well recognized. Methods: Caspase-1 inhibitor Z-YVAD-FMK and caspase-7 siRNA were used in tubular epithelial cell line NRK-52E (TECs) to test their effects on transforming growth factor-beta1 (TGF-β1) stimulation. In vivo, Unilateral ureteral obstruction (UUO) animal model was employed in wild-type (WT) and caspase-1 knock out (KO) (caspase-1-/-) mice. Results: In current study, we found that caspase-7 was obviously activated in cultured TECs stimulated by TGF-β1 and in UUO model of WT mice. While in UUO model of caspase-1 KO mice, the increased caspase-7 activation was suppressed significantly along with reduced trans-differentiation and minimized extracellular matrix (ECM) accumulation, as demonstrated by western blot, Masson trichrome staining and immunohistochemistry. In addition, pharmacological inhibition of caspase-1 dampened caspase-7 activation and TECs' transdifferentiation induced by TGF-β1 exposure, which was consistent with in vivo study. Notably, caspase-7 gene knock down by specific siRNA abrogated TGF-β1 driven TECs' trans-differentiation and reduced ECM accumulation. Conclusions: Our study associated inflammatory and apoptotic caspases in TIF for the first time and we further confirmed that caspase-1 activation is an upstream event of apoptotic caspase-7 induction in TIF triggered by UUO and in TECs mediated by TGF-β1 induced transdifferentiation. [ABSTRACT FROM AUTHOR]

Vasculogenic mimicry (VM) describes the process by which aggressive cancer cells form extracellular matrix-rich, vessel-like mesh works, which supply nutrients and oxygen. Furthermore, it offers a new route for tumor cell invasion and metastasis and thus a correspondingly poor prognosis and survival rate for affected patients. Effector caspases are well known for their apoptotic function, whereas a non-apoptotic function in tumor progression is highly disputed. Caspase-3, -6 and -7 are expressed in aggressive tumor cells in a non-mutated form, indicating an active function independent of apoptosis. This review summarizes the possible functions of the above-mentioned caspases in VM. We also discuss the possible involvement of caspases in potential mechanisms towards the formation of vessel-like structures. Furthermore, this review illustrates the importance of new studies in the ongoing investigation into the role of effector caspases in VM, invasion, and migration of aggressive tumor cells. [ABSTRACT FROM AUTHOR]